JPH116145A - Steel pipe pile equipped with threaded joint part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a threaded joint-equipped steel pipe pile that is exempted from influence working on the threaded joint part and free from loosening at the threaded joint part even though the steel pipe pile is turned reversely during execution of work by a method wherein a loosening-preventing device is provided at the threaded joint part. SOLUTION: The present steel pipe pile is composed of a steel pipe pile body 1 having an internally-threaded joint part 2 at its end a steel pipe pile body 3 having an externally-threaded joint part 4 at its end. While a collar part 6 is formed by extending the front end of the internally-threaded joint part 2, a cylindrical part 8 is formed in continuity at the tail end of the external thread 7 of the externally-threaded joint part 4 so that it can be inserted into the collar part 6, and a loosening-preventing device 10 for a threaded joint part 15 is provided at the collar part 6 and the cylindrical part 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe pile joined by a threaded joint, and more particularly, to a steel pipe pile with a threaded joint provided with means for preventing a screw from being loosened in the threaded joint. .

[0002]

2. Description of the Related Art Steel pipe piles joined by threaded joints are often used as landslide prevention piles or foundation piles. When used as landslide prevention piles, pre-boring is usually performed using a down-the-hole hammer. It is constructed by a construction method in which a steel pipe pile is built in this excavation hole. On the other hand, various construction methods are used when used as foundation piles.For example, when steel pipe piles are installed on soft ground, pre-boring may cause the excavation hole to collapse. Depending on the method, steel pipe piles are often built.

[0003]

The steel pipe pile joined by the threaded joint as described above has a screw tightened at the time of forward rotation so that the female threaded joint part and the male threaded joint part (shoulder part). Can come into contact with each other, thereby transmitting the torque. However, when a reverse torque is applied, the two threaded joints may be loosened and eventually come off. When a steel pipe pile is used as a foundation pile, the steel pipe pile may be rotated forward and reverse during construction.If the conventional construction technology is applied as it is, the threaded joint will loosen and the strength of this part will decrease. Not only that, the threaded joint may come off in some cases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. By providing means for preventing a screw from loosening in a threaded joint, a steel pipe can be formed during construction without affecting the strength of the threaded joint. It is an object of the present invention to obtain a steel pipe pile with a threaded joint which does not loosen even when the pile is rotated in the reverse direction.

[0005]

[Means for Solving the Problems]

(1) The steel pipe pile with a threaded joint according to the present invention is provided with a collar portion by extending a distal end portion of a female thread of the female threaded joint portion, and is connected to a screw base end portion of the male threaded joint portion. The collar portion is provided with a fittable cylindrical portion, and the collar portion and the cylindrical portion are provided with a means for preventing the threaded joint portion from loosening.

(2) The loosening prevention means of the above (1) can be provided by connecting the plurality of pin holes provided in the collar portion, the plurality of pin holes provided in the cylindrical portion, and the collar portion when screwing the steel pipe pile body. And a pin provided in both pin holes when the pin holes provided in the cylindrical portion are aligned.

[0007] (3) The loosening prevention means of the above (1) can be provided by connecting the plurality of screw holes provided in the collar portion, the plurality of screw holes provided in the cylindrical portion, and the collar portion when screwing the steel pipe pile body. And a bolt screwed into both screw holes when the screw holes provided in the cylindrical portion are aligned.

(4) The pin hole or screw hole and the pin or bolt according to (2) or (3) are formed in a tapered shape in which the diameter of the central portion of the steel pipe pile main body is reduced. (5) Either the pin hole or the screw hole provided in the collar portion or the cylindrical portion of (2), (3) or (4) is a hole larger than the outer diameter of the pin or the bolt.

(6) The pin hole or the screw hole provided in the cylindrical portion of the externally threaded joint (2), (3) or (4) is a bottomed hole or a bottomed screw hole. (7) The above-mentioned (2), (3) or (4) a pin hole or a screw hole provided in the cylindrical portion of the male threaded joint portion is a bottomed hole having an inner diameter larger than the outer diameter of the pin or the bolt. (8) The screw hole provided in the cylindrical portion of the external threaded joint portion (3) or (4) is a bottomed hole having an inner diameter larger than the outer diameter of the bolt, and is inserted into the bottomed hole of the bolt. Is formed in a columnar shape.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 is a partial cross-sectional view showing a main part of Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes a first steel pipe pile main body having an internal threaded joint portion 2, and a collar portion 6 is extended from a distal end portion of the internal thread 5 to be continuous with the internal thread 5. 3 is a second steel pipe pile main body having a male threaded joint part 4 screwed to the female threaded joint part 2, and a base part of the male thread 7 is provided with a collar part 6 of the female threaded joint part 2.
Is provided with a cylindrical portion 8 which can be freely inserted, and a shoulder portion 9 is formed at the base of the cylindrical portion 8. Reference numeral 10 denotes a means for preventing the threaded joint from loosening.
And a plurality of pin holes 12 penetrated at equal intervals in the cylindrical portion 8 of the male threaded joint 3.
And a pin 13 fitted when the pin holes 11 and 12 are aligned.

In order to join the first and second steel pipe pile bodies 1 and 3 configured as described above, the second steel pipe pile body 3 is connected to the female thread joint 2 of the first steel pipe pile body 1. The male screw joint 4 is screwed. Then, near the end of the threaded joint between the female threaded joint part 2 and the male threaded joint part 4, that is, before the collar part 6 comes into contact with the shoulder part 9, the pin holes 11, 1 of the joint parts 2, 4 are formed.
When the two are aligned, the screwing is stopped and the pin holes 11, 1
The pin 13 is press-fitted or beaten into 2 and set. Thereby, even if the steel pipe pile rotates in the opposite direction, the screw joint portion 15 is restrained by the pin 13 and therefore does not loosen.

In this case, it is desirable that the end of the pin 13 does not protrude from the outer peripheral surface of the female screw joint 2 and the inner peripheral surface of the male screw joint 4. If it protrudes from the outer peripheral surface, when rotating the steel pipe pile, a resistance will be generated between the pin 13 and the ground, and if it protrudes from the inner peripheral surface, mortar will be injected into the steel pipe pile. This is an obstacle when arranging pipes or tremy pipes.

By the way, when fixing the female screw joint portion 2 and the male screw joint portion 4 with the pins 13, one pin hole 11, 12 is provided in the collar portion 6 and the cylindrical portion 8 of both joint portions 2, 4.
To complete the threaded joining of the two joints 2 and 4,
Therefore, it is best if the two pin holes 11 and 12 can be aligned and the pin 13 can be set in the pin holes 11 and 12 at the same time when the tip of the collar portion 6 comes into contact with the shoulder portion 9. Impossible.

Therefore, for example, the first and second steel pipe piles 1 and 3 having the female screw joint portion 2 and the male screw joint portion 4 are screwed at a factory in advance, and the collar portion 6 is brought into contact with the shoulder portion 9 in contact therewith. It is also conceivable to drill the pin holes 11 and 12 communicating with the cylindrical portion 8, but this would increase one step, which is not preferable. In addition, in this case, the combination of the first and second steel pipe pile bodies 1 and 3 is fixed, so that the compatibility is lost with steel pipe piles having the same shape and the same dimensions. For this reason, it is necessary to always manage the combination of the steel pipe pile main bodies 1 and 3 during the manufacturing process of the steel pipe pile, and also to constantly manage the combination during loading into the construction site and at the construction site. Thus, production management and construction management are extremely troublesome and impractical.

In this embodiment, a collar portion 6 is provided at the distal end of the female screw joint portion 2, and a cylindrical portion 8 which can be inserted into the collar portion 6 is provided at the proximal end of the thread of the male screw joint portion 3. 5
And threaded joint 1 without any processing on male thread 7
A plurality of pin holes 11 and 12 are provided in the collar portion 6 and the cylindrical portion 8 which do not affect the proof stress of 5, and screwing is stopped when the pin holes 11 and 12 are aligned near the end of the screw joint. Since the pins 13 are inserted into the holes 11 and 12, the pins 13 can be easily and reliably set.

Second Embodiment FIGS. 2 to 6 are explanatory views showing the main parts of a second embodiment of the present invention. In the first embodiment, a plurality of pin holes 11 and 12 are provided in the collar portion 6 of the female screw joint portion 2 and the cylindrical portion 8 of the male screw joint portion 4 as the loosening prevention means 10, respectively.
Pin holes 11, 1 aligned by screwing both joints 2, 4
2 shows a case in which the pin 13 is set, but in the present embodiment, the screw holes 16, 1 are used instead of the pin holes 11, 12.
7 and a bolt 18 in place of the pin 13.

In FIG. 2, reference numeral 16 denotes a plurality of screw holes provided in the collar portion 6 of the female screw joint portion 2, and 17 denotes a male screw joint portion 4.
A plurality of screw holes provided in the cylindrical portion 8 of the screw hole 18;
These bolts are screwed in when the members 6 and 17 are aligned. Also in this embodiment, the threaded joint 4 of the second steel pipe pile main body 3 is screwed into the female threaded joint 2 of the first steel pipe pile main body 1 in substantially the same manner as in the first embodiment, and screwed. The bolt 18 is screwed into the screw holes 16 and 17 which are aligned before the end of the bolt, and the loosening prevention means 10 is formed.

FIG. 3 shows an example in which the collar 6 of the female thread joint 2 is used.
And a plurality of tapered screw holes 19, 20 whose central portions of both steel pipe pile bodies 1, 3 are reduced in diameter in the cylindrical portion 8 of the male screw joint portion 4, and a bolt 21 having a tapered screw in the tapered screw holes 19, 20. The function and effect are the same as those in the example of FIG. 2, but the penetration of the bolt 21 can be prevented.

In the example of FIG. 4, a screw hole 17 provided in the cylindrical portion 6 of the threaded joint portion 4 of the example of FIG.
The bolt 18a is shortened in accordance with the bottomed screw hole 17a. Thereby, even if the bolt 18a is fully screwed, it is possible to prevent the distal end portion from projecting from the cylindrical portion 6 of the male threaded joint portion 4 to the inner surface or from penetrating therethrough.

In the example of FIG. 5, a bottomed hole 22 having an inner diameter larger than the outer diameter of the bolt 18a is provided in the cylindrical portion 8 of the threaded joint portion 4 of the example of FIG. 4 instead of the bottomed screw hole 17a. It is.
Although not shown, the screw hole 16 provided in the collar portion 6 of the female screw joint portion 2 is a through hole having an inner diameter larger than the outer diameter of the bolt 18a, and a bottomed screw is formed in the cylindrical portion 8 of the male screw joint portion 4. Holes may be provided. With this configuration, the workability of the bottomed hole 22 or the through hole is improved, and the bolt is not applied to the bolt 18a when the steel pipe pile is normally rotated, and the screw is only screwed when rotated in the reverse direction. The joint 15 has a function of preventing loosening.

The example of FIG. 6 is different from the example of FIG.
Instead of 8a, a screw is provided only in a portion to be screwed into the screw hole 16, and a bolt 23 having a lower portion formed in a cylindrical shape is used. In addition, as described in the example of FIG.
In the case where 6 is a through hole and the bottomed hole 22 is a bottomed screw hole, a screw may be provided only at a portion to be screwed into the bottomed screw hole, and a bolt having an upper portion formed in a cylindrical shape may be used. By the way, in a steel pipe pile with a threaded joint, after a rotational force is applied to the threaded joint 15 by construction or the like, the threaded joint 15 may be disassembled for some reason. In such a case, the screw thread provided on the bolt may be broken by the rotational force, and may not be dislodged and cannot be dismantled. In this example, since the screw thread of the part to which the load is applied during rotation of the steel pipe pile of the bolt was removed and formed in a columnar shape,
There is no risk that the bolt will not come off.

In this embodiment, substantially the same functions and effects as those of the first embodiment can be obtained, but the loosening prevention means 1
Since 0 is composed of the screw holes and the bolts, the bolts can be prevented from falling off during construction. Embodiment 1
Also, according to the example of FIGS. 3 to 5 of the present embodiment, the pin holes 11 and 12 and the pin 13 are formed in a tapered shape, or the pin hole 12 is a bottomed pin hole.
One inner diameter of the pin 12 can be larger than the outer diameter of the pin 13. Also, the examples of FIGS. 4 to 6 can be applied to the example of FIG. 3 of the present embodiment.

Embodiment 3 In this embodiment, as shown in FIG. 7, a cylindrical portion 8a is provided continuously at the proximal end of the screw of the female screw joint 2, and the distal end of the external thread 7 of the male screw joint 4 is provided. The collar part 6a is extended to the part,
The cylindrical portion 8a and the collar portion 6a are provided with a plurality of screw holes 16a and 17a, respectively, and when the screw holes 16a and 17a are aligned, a bolt 18 is screwed in to prevent loosening.
0. As in the case of the first embodiment, a pin hole may be provided instead of the screw holes 16a and 17a, and a pin may be set in the pin hole.
Each of the examples of FIGS. 3 to 6 of the second embodiment can be applied. Also in the present embodiment, it is possible to obtain substantially the same operation and effect as in the first or second embodiment.

Embodiment 4 This embodiment is a combination of Embodiments 2 and 3 with a screw joint 1
In this embodiment, loosening prevention means 10a and 10b are provided on both sides of the zero. Also in the present embodiment, the examples of FIGS. 3 to 6 of the first or second embodiment can be applied. According to this embodiment, the same operation and effect as those of the first to third embodiments can be obtained, and the function of preventing loosening of the screw can be further improved.

In the present invention, a plurality of pin holes 11, 12 or screw holes 16, 17 and the like (hereinafter referred to as pin holes, etc.) are respectively formed in the collar portion 6 of the female screw joint portion 2 and the cylindrical portion 8 of the male screw joint portion 4. When the joints 2 and 4 are screwed together at the site, pin holes 11 and 1 etc. are provided before the end of the screw joint.
Stop screwing in the position where 2 is aligned,
12 is a pin 13 or a bolt 18 (hereinafter referred to as a pin or the like)
Is inserted or screwed in, so that the threaded joint portion 15 needs to be designed to have a sufficient strength even if the shoulder portion 9 does not abut. In particular, with regard to the compressive strength, it is necessary to ensure a sufficient screw thread so that the load is not transmitted by the shoulder portion 9 and the screw thread alone can withstand the load.

Since the amount of clearance at the shoulder portion = the amount of thread overlap = the amount of transmission of compressive force, the maximum amount of clearance at the shoulder portion (g in FIG. 1) for the threaded joint portion 15 to have a sufficient compressive strength is: , Effective thread number, thread shape, material strength and the like. On the other hand, the distance that the screw joint 15 moves in the axial direction until the pin holes 11 and 12 are aligned is determined by the pin holes 11 and 12 and the pitch of the thread of the screw joint 15. That is, the shoulder portion 9
The shoulder gap g when the pin holes 11 and 12 are aligned just before the contact is calculated by “thread pitch ÷ number of pin holes”.

(Embodiment) In the embodiment, in the female threaded joint part 2 and the male threaded joint part 4 made of HITEN 780 having an outer diameter of 600 mm and a thickness of 16 mm, a shoulder gap g of a maximum of 2.1 mm at the time of joining piles. The threaded joint part 15 was designed on the assumption that this would occur. That is, the female thread joint part 2 and the male thread joint part 4 in FIG.
A female thread 5 and a male thread 7 are provided, a collar section 6 having a length of 100 mm and a thickness of 10 mm is provided at a distal end of the female thread joint section 2, and a length is continuously provided at a screw base end of the male thread joint section 4. A cylindrical portion 8 of 100 mm was provided. Further, the collar 6 and the cylindrical portion 8 have a diameter of 2 mm.
Four 5 mm pin holes 11 and 12 were provided at equal intervals, and four pins 13 having an outer diameter of 25 mm and a length of 15 mm were provided.

The female threaded joint 2 and the male threaded joint 4 are screwed together and the shoulder 9 is abutted.
Three steel pipe piles were tested in which the gap g of the shoulder 9 was 2.1 mm and the gap g of the shoulder 9 was 2.1 mm and the pins 13 were set in the pin holes 11 and 12, respectively. The body was subjected to a compression test and a bending test to confirm the joint strength.

In the compression test, only the threaded joint portion 15 was sandwiched between steel plates and a compressive force was applied to the central axis. As a result, it was confirmed that all the three members exhibited almost the same behavior and had a proof stress greater than the design load. . The bending test is a four-point bending test.
A steel pipe pile main body having a proof strength equal to or greater than the threaded joint 15 was welded and joined to the female threaded joint 2 and the male threaded joint 4, respectively. As a result of calculating the edge yield load and the overall yield load for the weakest cross section of the threaded joint portion 15, it was confirmed that all of the three members had a yield strength equal to or higher than the calculated value.

In the above embodiment, since the number of the pin holes 11 and 12 is four and the number of the pins 13 is four, the shoulder when the pin 13 is set before the screw joint part 15 contacts the shoulder part 9 is set. Although the gap amount g was 2.1 mm, both or one of the pin holes 11 and 12 of the female screw joint portion 2 and the male screw joint portion 4 were removed as long as the proof stress was not reduced on the screw joint portion 15. By providing a large number,
The rotation angle until the pin holes 11, 12 are aligned can be reduced. As a result, the shoulder gap g can be reduced.

In the above-described embodiment, the female screw joint 2 and the male screw joint 4 are provided with the pin holes 11 and 12 and
Has been described, but the pin holes 11, 12
The same applies to the case where screw holes 16 and 17 are used in place of bolts and bolts 18 and the like are used in place of pins 13.

Since the compression strength of the threaded joint 15 is determined by the number of threads and the bending strength is determined by the section modulus of the base end of the screw, as in the present invention, the pin holes 11 and 1 are formed in the collar 6 and the cylindrical portion 8.
In the case where 2 or the screw holes 16 and 17 are provided, there is almost no effect on the proof stress of the screw joint portion 15. Further, in the present invention, since the external force such as the axial force and the bending moment after the completion of the construction work of the steel pipe pile is covered by the threaded joint portion 15, a large external force does not act on the pin 13 or the bolt 18 after the construction. .

In addition, with respect to the axial force, the screw joint 1
Since the threads of No. 5 come into contact with each other in advance, the pins 11, 1
No axial force acts on the bolt 2 or the bolt 18 or the like. However, since the shoulder portion 9 does not come into contact, the component force of the axial force due to the inclination of the screw thread acts as a rotational force and acts on the pins 11, 12 or the bolt 18 or the like.

However, for example, φ600, t16
SKK400 steel pipe pile with allowable stress of 1,400kg / cm
^When an axial force equivalent to ² is applied, the rotational force due to the inclination of the screw thread (with a pitch of 8.4 mm) is about 1.5 tm. In addition, the friction coefficient between the threads, the ground coefficient, and the peripheral frictional force acting as a resisting force on the steel pipe pile installed in the ground, it is generated from the inclination of the thread due to the axial force after the steel pipe pile is installed The rotational force is insignificant compared to the rotational force during construction, and pins or bolts designed based on construction conditions have sufficient strength to withstand this. Further, the foundation pile is generally restricted in rotational force at the point of load application, and does not act on or generate a rotational force on the steel pipe pile after being installed in the ground.

[0035]

【The invention's effect】

(1) A steel pipe pile with a threaded joint according to the present invention includes a steel pipe pile main body having a female threaded joint at an end and a steel pipe pile main body having a threaded joint at an end. The distal end of the female screw is extended to provide a collar portion, and a cylindrical portion that can be continuously fitted into the collar portion is provided at the proximal end of the screw of the male threaded joint portion. Since the loosening prevention means is provided, the loosening of the threaded joint can be prevented even when a reverse rotational force is applied to the steel pipe pile during the construction work without affecting the strength of the threaded joint.

(2) A plurality of pin holes provided in the collar portion, a plurality of pin holes provided in the cylindrical portion, and the collar portion when the steel pipe pile body is screw-connected to the looseness prevention means of (1). When the pin holes provided in the cylindrical portion are aligned with each other, the pins are provided in both pin holes, so that the screw joint can be prevented from being loosened with a simple structure.

(3) A plurality of screw holes provided in the collar portion, a plurality of screw holes provided in the cylindrical portion, and the collar portion when the steel pipe pile main body is screw-connected with the collar portion are provided with the loosening prevention means of (1). Since the screw holes provided in the cylinder are aligned with the bolts that screw into both screw holes when aligned, the structure of the screw joint can be prevented from loosening with a simple structure, and the bolt may fall off during construction. Absent.

(4) Since the pin hole or screw hole and the pin or bolt of the above (2) or (3) are formed in a tapered shape in which the central portion of the steel pipe pile main body is reduced in diameter, the above (2) or (3) ) Is obtained, and the pin or bolt does not penetrate inward when the pin or bolt is set.

(5) Since one of the pin hole and the screw hole provided in the collar portion or the cylindrical portion of the above (2), (3) or (4) is a hole larger than the outer diameter of the pin or the bolt. ,
No load is applied to the portion inside the large hole of the pin or bolt during the construction work of the steel pipe pile, and the locking function is exhibited only when it is rotated in the opposite direction.

(6) Since the pin hole or the screw hole provided in the cylindrical portion of the male threaded joint (2), (3) or (4) is a bottomed hole or a bottomed screw hole, the pin or the bolt is used. Can be prevented from penetrating inward when setting.

(7) The above-mentioned (2), (3) or (4) the pin hole or the screw hole provided in the cylindrical portion of the external threaded joint is a bottomed hole having an inner diameter larger than the outer diameter of the pin or bolt. Therefore, the same effects as the above (5) and (6) can be obtained.

(8) The threaded hole provided in the cylindrical portion of the male threaded joint according to any one of (3) to (7) is a bottomed hole having an inner diameter larger than the outer diameter of the bolt, and the bolted bottom is provided. Since the portion to be inserted into the hole is formed in a cylindrical shape, the effects (5) and (6) can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view illustrating a main part of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a main part of a second embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a main part of another example of Embodiment 2 of the present invention.

FIG. 4 is an explanatory diagram showing a main part of another example of Embodiment 2 of the present invention.

FIG. 5 is an explanatory diagram showing a main part of another example of Embodiment 2 of the present invention.

FIG. 6 is an explanatory diagram illustrating a main part of another example of the second embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a main part of a third embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a main part of a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st steel pipe pile main body 2 Female thread joint part 3 2nd steel pipe pile main body 4 Male thread joint part 6 Collar part 8 Cylindrical part 9 Shoulder part 10 Loose prevention means 11, 12 Pin hole 13 Pin 15 Screw joint part 16, 17 Screw Hole 17a Screw Hole with Bottom 18, 18a Bolt 19, 20 Tapered Screw Hole 21 Bolt with Tapered Screw 22 Hole 23 Bolt with Partial Column

Claims (8)

[Claims] 1. A steel pipe pile body having a female thread joint at an end, and a steel pipe pile body having a thread joint at an end, wherein a distal end of a female thread of the female thread is extended. A collar portion is provided, a cylindrical portion that can be continuously fitted into the collar portion is provided at a screw base end portion of the male threaded joint portion, and a loosening prevention means for the threaded joint portion is provided at the collar portion and the cylindrical portion. A steel pipe pile with a threaded joint part. 2. A looseness preventing means is provided in a plurality of pin holes provided in a collar portion, a plurality of pin holes provided in a cylindrical portion, and in the collar portion and the cylindrical portion when the steel pipe pile body is screwed. 2. A steel pipe pile with a threaded joint according to claim 1, wherein said steel pipe pile is constituted by pins installed in said pin holes when said pin holes are aligned. 3. A loosening prevention means is provided in the collar portion and the cylindrical portion when screwing the plurality of screw holes provided in the collar portion, the plurality of screw holes provided in the cylindrical portion, and the steel pipe pile main body. 2. A steel pipe pile with a screw joint according to claim 1, wherein said steel pipe pile is formed by a bolt which is screwed into each of said screw holes when said screw holes are aligned. 4. A steel pipe pile with a threaded joint according to claim 2, wherein the pin hole or the screw hole and the pin or the bolt are formed in a tapered shape in which the diameter of the central portion of the steel pipe pile body is reduced. 5. The screw according to claim 2, wherein one of the pin hole and the screw hole provided in the collar portion or the cylindrical portion is a hole larger than the outer diameter of the pin or the bolt. Steel pipe pile with joint. 6. A steel pipe with a screw joint according to claim 2, wherein the pin hole or the screw hole provided in the cylindrical portion of the male screw joint is a bottomed hole or a bottomed screw hole. Pile. 7. The pin hole or the screw hole provided in the cylindrical portion of the male screw joint portion is a bottomed hole having an inner diameter larger than the outer diameter of the pin or the bolt. Steel pipe pile with screw joint. 8. A screw hole provided in the cylindrical portion of the male threaded joint portion is a bottomed hole having an inner diameter larger than the outer diameter of the bolt, and a portion of the bolt inserted into the bottomed hole is formed in a cylindrical shape. The steel pipe pile with a threaded joint part according to claim 3 or 4, wherein: